MOS Devices for Low-Voltage and Low-Energy Applications (Hardcover)

<內容簡介>

Helps readers understand the physics behind MOS devices for low-voltage and low-energy applications

‧ Based on timely published and unpublished work written by expert authors
‧ Discusses various promising MOS devices applicable to low-energy environmental and biomedical uses
‧ Describes the physical effects (quantum, tunneling) of MOS devices
‧ Demonstrates the performance of devices, helping readers to choose right devices applicable to an industrial or consumer environment
‧ Addresses some Ge-based devices and other compound-material-based devices for high-frequency applications and future development of high performance devices.

'Seemingly innocuous everyday devices such as smartphones, tablets and services such as on-line gaming or internet keyword searches consume vast amounts of energy. Even when in standby mode, all these devices consume energy. The upcoming “Internet of Things” (IoT) is expected to deploy 60 billion electronic devices spread out in our homes, cars and cities.

Britain is already consuming up to 16 per cent of all its power through internet use and this rate is doubling every four years. According to The UK’s Daily Mail May (2015), if usage rates continue, all of Britain's power supply could be consumed by internet use in just 20 years. In 2013, U.S. data centers consumed an estimated 91 billion kilowatt-hours of electricity, corresponding to the power generated by seventeen 1000-megawatt nuclear power plants. Data center electricity consumption is projected to increase to roughly 140 billion kilowatt-hours annually by 2020, the equivalent annual output of 50 nuclear power plants. (Natural Resources Defense Council, USA, Feb. 2015)

All these examples stress the urgent need for developing electronic devices that consume as little energy as possible. The book “MOS Devices for Low-Voltage and Low-Energy Applications” explores the different transistor options that can be utilized to achieve that goal. It describes in detail the physics and performance of transistors that can be operated at low voltage and consume little power, such as subthreshold operation in bulk transistors, fully depleted SOI devices, tunnel FETs, multigate and gate-all-around MOSFETs. Examples of low-energy circuits making use of these devices are given as well.
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Preface xv

Acknowledgments xvi

Part I INTRODUCTION TO LOW?VOLTAGE AND LOW?ENERGY DEVICES 1

1 Why Are Low?Voltage and Low?Energy Devices Desired? 3

References 4

2 History of Low?Voltage and Low?Power Devices 5

2.1 Scaling Scheme and Low?Voltage Requests 5

2.2 Silicon?on?Insulator Devices and Real History 8

References 10

3 Performance Prospects of Subthreshold Logic Circuits 12

3.1 Introduction 12

3.2 Subthreshold Logic and its Issues 12

3.3 Is Subthreshold Logic the Best Solution? 13

References 13

Part II SUMMARY OF PHYSICS OF MODERN SEMICONDUCTOR DEVICES 15

4 Overview 17

References 18

5 Bulk MOSFET 19

5.1 Theoretical Basis of Bulk MOSFET Operation 19

5.2 Subthreshold Characteristics: “OFF State” 19

5.2.1 Fundamental Theory 19

5.2.2 Influence of BTBT Current 23

5.2.3 Points to Be Remarked 24

5.3 Post?Threshold Characteristics: “ON State” 24

5.3.1 Fundamental Theory 24

5.3.2 Self?Heating Effects 26

5.3.3 Parasitic Bipolar Effects 27

5.4 Comprehensive Summary of Short?Channel Effects 27

References 28

6 SOI MOSFET 29

6.1 Partially Depleted Silicon?on?Insulator Metal Oxide Semiconductor Field?Effect Transistors 29

6.2 Fully Depleted (FD) SOI MOSFET 30

6.2.1 Subthreshold Characteristics 30

6.2.2 Post?Threshold Characteristics 36

6.2.3 Comprehensive Summary of Short?Channel Effects 41

6.3 Accumulation?Mode (AM) SOI MOSFET 41

6.3.1 Aspects of Device Structure 41

6.3.2 Subthreshold Characteristics 42

6.3.3 Drain Current Component (I) – Body Current (ID,body) 43

6.3.4 Drain Current Component (II) – Surface Accumulation

Layer Current (ID,acc) 45

6.3.5 Optional Discussions on the Accumulation Mode SOI MOSFET 45

6.4 FinFET and Triple?Gate FET 46

6.4.1 Introduction 46

6.4.2 Device Structures and Simulations 46

6.4.3 Results and Discussion 47

6.4.4 Summary 49

6.5 Gate?all?Around MOSFET 50

References 51

7 Tunnel Field?Effect Transistors (TFETs) 53

7.1 Overview 53

7.2 Model of Double?Gate Lateral Tunnel FET and Device Performance Perspective 53

7.2.1 Introduction 53

7.2.2 Device Modeling 54

7.2.3 Numerical Calculation Results and Discussion 61

7.2.4 Summary 65

7.3 Model of Vertical Tunnel FET and Aspects of its Characteristics 65

7.3.1 Introduction 65

7.3.2 Device Structure and Model Concept 65

7.3.3 Comparing Model Results with TCAD Results 69

7.3.4 Consideration of the Impact of Tunnel Dimensionality on Drivability 72

7.3.5 Summary 75

7.4 Appendix Integration of Eqs. (7.14)–(7.16) 76

References 78

Part III POTENTIAL OF CONVENTIONAL BULK MOSFETs 81

8 Performance Evaluation of Analog Circuits with Deep Submicrometer MOSFETs in the Subthreshold Regime of Operation 83

8.1 Introduction 83

8.2 Subthreshold Operation and Device Simulation 84

8.3 Model Description 85

8.4 Results 86

8.5 Summary 90

References 90

9 Impact of Halo Doping on the Subthreshold Performance of Deep?Submicrometer CMOS Devices and Circuits for Ultralow Power Analog/Mixed?Signal Applications 91

9.1 Introduction 91

9.2 Device Structures and Simulation 92

9.3 Subthreshold Operation 93

9.4 Device Optimization for Subthreshold Analog Operation 95

9.5 Subthreshold Analog Circuit Performance 98

9.6 CMOS Amplifiers with Large Geometry Devices 105

9.7 Summary 106

References 107

10 Study of the Subthreshold Performance and the Effect of Channel Engineering on Deep Submicron Single?Stage CMOS Amplifiers 108

10.1 Introduction 108

10.2 Circuit Description 108

10.3 Device Structure and Simulation 110

10.4 Results and Discussion 110

10.5 PTAT as a Temperature Sensor 116

10.6 Summary 116

References 116

11 Subthreshold Performance of Dual?Material Gate CMOS Devices and Circuits for Ultralow Power Analog/Mixed?Signal Applications 117

11.1 Introduction 117

11.2 Device Structure and Simulation 118

11.3 Results and Discussion 120

11.4 Summary 126

References 127

12 Performance Prospect of Low?Power Bulk MOSFETs 128

Reference 129

Part IV POTENTIAL OF FULLY?DEPLETED SOI MOSFETs 131

13 Demand for High?Performance SOI Devices 133

14 Demonstration of 100 nm Gate SOI CMOS with a Thin Buried Oxide Layer and its Impact on Device Technology 134

14.1 Introduction 134

14.2 Device Design Concept for 100 nm Gate SOI CMOS 134

14.3 Device Fabrication 136

14.4 Performance of 100?nm? and 85?nm Gate Devices 137

14.4.1 Threshold and Subthreshold Characteristics 137

14.4.2 Drain Current (ID)?Drain Voltage (VD) and ID?Gate Voltage (VG) Characteristics of 100?nm?Gate MOSFET/SIMOX 138

14.4.3 ID–VD and ID–VG Characteristics of 85?nm?Gate MOSFET/SIMOX 142

14.4.4 Switching Performance 142

14.5 Discussion 142

14.5.1 Threshold Voltage Balance in Ultrathin CMOS/SOI Devices 142

14.6 Summary 144

References 145

15 Discussion on Design Feasibility and Prospect of High?Performance Sub?50 nm Channel Single?Gate SOI MOSFET Based on the ITRS Roadmap 147

15.1 Introduction 147

15.2 Device Structure and Simulations 148

15.3 Proposed Model for Minimum Channel Length 149

15.3.1 Minimum Channel Length Model Constructed using Extract A 149

15.3.2 Minimum Channel Length Model Constructed using Extract B 150

15.4 Performance Prospects of Scaled SOI MOSFETs 152

15.4.1 Dynamic Operation Characteristics of Scaled SG SOI MOSFETs 152

15.4.2 Tradeoff and Optimization of Standby Power Consumption and Dynamic Operation 157

15.5 Summary 162

References 162

16 Performance Prospects of Fully Depleted SOI MOSFET?Based Diodes Applied to Schenkel Circuits for RF?ID Chips 164

16.1 Introduction 164

16.2 Remaining Issues with Conventional Schenkel Circuits and an Advanced Proposal 165

16.3 Simulation?Based Consideration of RF Performance of SOI?QD 172

16.4 Summary 176

16.5 Appendix: A Simulation Model for Minority Carrier Lifetime 177

16.6 Appendix: Design Guideline for SOI?QDs 177

References 178

17 The Potential and the Drawbacks of Underlap Single?Gate Ultrathin SOI MOSFET 180

17.1 Introduction 180

17.2 Simulations 181

17.3 Results and Discussion 183

17.3.1 DC Characteristics and Switching Performance: Device A 183

17.3.2 RF Analog Characteristics: Device A 184

17.3.3 Impact of High?κ Gate Dielectric on Performance of USU SOI MOSFET Devices: Devices B and C 185

17.3.4 Impact of Simulation Model on Simulation Results 189

17.4 Summary 192

References 192

18 Practical Source/Drain Diffusion and Body Doping Layouts for High?Performance and Low?Energy Triple?Gate SOI MOSFETs 194

18.1 Introduction 194

18.2 Device Structures and Simulation Model 195

18.3 Results and Discussion 196

18.3.1 Impact of S/D?Underlying Layer on ION, IOFF, and Subthreshold Swing 196

18.3.2 Tradeoff of Short?Channel Effects and Drivability 196

18.4 Summary 201

References 201

19 Gate Field Engineering and Source/Drain Diffusion Engineering for High?Performance Si Wire Gate?All?Around MOSFET and Low?Power Strategy in a Sub?30 nm?Channel Regime 203

19.1 Introduction 203

19.2 Device Structures Assumed and Physical Parameters 204

19.3 Simulation Results and Discussion 206

19.3.1 Performance of Sub?30 nm?Channel Devices and Aspects of Device Characteristics 206

19.3.2 Impact of Cross?Section of Si Wire on Short?Channel Effects and Drivability 212

19.3.3 Minimizing Standby Power Consumption of GAA SOI MOSFET 216

19.3.4 Prospective Switching Speed Performance of GAA SOI MOSFET 217

19.3.5 Parasitic Resistance Issues of GAA Wire MOSFETs 218

19.3.6 Proposal for Possible GAA Wire MOSFET Structure 220

19.4 Summary 221

19.5 Appendix: Brief Description of Physical Models in Simulations 221

References 225

20 Impact of Local High?κ Insulator on Drivability and Standby Power of Gate?All?Around SOI MOSFET 228

20.1 Introduction 228

20.2 Device Structure and Simulations 229

20.3 Results and Discussion 230

20.3.1 Device Characteristics of GAA Devices with Graded?Profile Junctions 230

20.3.2 Device Characteristics of GAA Devices with Abrupt Junctions 235

20.3.3 Behaviors of Drivability and Off?Current 237

20.3.4 Dynamic Performance of Devices with Graded?Profile Junctions 239

20.4 Summary 239

References 240

Part V POTENTIAL OF PARTIALLY DEPLETED SOI MOSFETs 241

21 Proposal for Cross?Current Tetrode (XCT) SOI MOSFETs: A 60 dB Single?Stage CMOS Amplifier Using High?Gain Cross?Current Tetrode MOSFET/SIMOX 243

21.1 Introduction 243

21.2 Device Fabrication 244

21.3 Device Characteristics 245

21.4 Performance of CMOS Amplifier 247

21.5 Summary 249

References 249

22 Device Model of the XCT?SOI MOSFET and Scaling Scheme 250

22.1 Introduction 250

22.2 Device Structure and Assumptions for Modeling 251

22.2.1 Device Structure and Features of XCT Device 251

22.2.2 Basic Assumptions for Device Modeling 253

22.2.3 Derivation of Model Equations 254

22.3 Results and Discussion 258

22.3.1 Measured Characteristics of XCT Devices 258

22.4 Design Guidelines 261

22.4.1 Drivability Control 261

22.4.2 Scaling Issues 262

22.4.3 Potentiality of Low?Energy Operation of XCT CMOS Devices 265

22.5 Summary 267

22.6 Appendix: Calculation of MOSFET Channel Current 267

22.7 Appendix: Basic Condition for Drivability Control 271

References 271

23 Low?Power Multivoltage Reference Circuit Using XCT?SOI MOSFET 274

23.1 Introduction 274

23.2 Device Structure and Assumptions for Simulations 274

23.2.1 Device Structure and Features 274

23.2.2 Assumptions for Simulations 277

23.3 Proposal for Voltage Reference Circuits and Simulation Results 278

23.3.1 Two?Reference Voltage Circuit 278

23.3.2 Three?Reference Voltage Circuit 283

23.4 Summary 283

References 284

24 Low?Energy Operation Mechanisms for XCT?SOI CMOS Devices: Prospects for a Sub?20 nm Regime 285

24.1 Introduction 285

24.2 Device Structure and Assumptions for Modeling 286

24.3 Circuit Simulation Results of SOI CMOS and XCT?SOI CMOS 288

24.4 Further Scaling Potential of XCT?SOI MOSFET 291

24.5 Performance Expected from the Scaled XCT?SOI MOSFET 292

24.6 Summary 296

References 296

Part VI QUANTUM EFFECTS AND APPLICATIONS – 1 297

25 Overview 299

References 299

26 Si Resonant Tunneling MOS Transistor 301

26.1 Introduction 301

26.2 Configuration of SRTMOST 302

26.2.1 Structure and Electrostatic Potential 302

26.2.2 Operation Principle and Subthreshold Characteristics 304

26.3 Device Performance of SRTMOST 307

26.3.1 Transistor Characteristics of SRTMOST 307

26.3.2 Logic Circuit Using SRTMOST 310

26.4 Summary 312

References 312

27 Tunneling Dielectric Thin?Film Transistor 314

27.1 Introduction 314

27.2 Fundamental Device Structure 315

27.3 Experiment 315

27.3.1 Experimental Method 315

27.3.2 Calculation Method 317

27.4 Results and Discussion 320

27.4.1 Evaluation of SiNx Film 320

27.4.2 Characteristics of the TDTFT 320

27.4.3 TFT Performance at Low Temperatures 324

27.4.4 TFT Performance at High Temperatures 324

27.4.5 Suppression of the Hump Effect by the TDTFT 330

27.5 Summary 336

References 336

28 Proposal for a Tunnel?Barrier Junction (TBJ) MOSFET 339

28.1 Introduction 339

28.2 Device Structure and Model 339

28.3 Calculation Results 340

28.4 Summary 343

References 343

29 Performance Prediction of SOI Tunneling?Barrier?Junction MOSFET 344

29.1 Introduction 344

29.2 Simulation Model 345

29.3 Simulation Results and Discussion 349

29.3.1 Fundamental Properties of TBJ MOSFET 349

29.3.2 Optimization of Device Parameters and Materials 349

29.4 Summary 357

References 357

30 Physics?Based Model for TBJ?MOSFETs and High?Frequency Performance Prospects 358

30.1 Introduction 358

30.2 Device Structure and Device Model for Simulations 359

30.3 Simulation Results and Discussion 360

30.3.1 Current Drivability 361

30.3.2 Threshold Voltage Issue 362

30.3.3 Subthreshold Characteristics 363

30.3.4 Radio?Frequency Characteristics 363

30.4 Summary 365

References 365

31 Low?Power High?Temperature?Operation?Tolerant (HTOT) SOI MOSFET 367

31.1 Introduction 367

31.2 Device Structure and Simulations 368

31.3 Results and Discussion 371

31.3.1 Room?Temperature Characteristics 371

31.3.2 High?Temperature Characteristics 373

31.4 Summary 377

References 379

Part VII QUANTUM EFFECTS AND APPLICATIONS – 2 381

32 Overview of Tunnel Field?Effect Transistor 383

References 385

33 Impact of a Spacer Dielectric and a Gate Overlap/Underlap on the Device Performance of a Tunnel Field?Effect Transistor 386

33.1 Introduction 386

33.2 Device Structure and Simulation 387

33.3 Results and Discussion 387

33.3.1 Effects of Variation in the Spacer Dielectric Constant 387

33.3.2 Effects of Variation in the Spacer Width 391

33.3.3 Effects of Variation in the Source Doping Concentration 392

33.3.4 Effects of a Gate?Source Overlap 394

33.3.5 Effects of a Gate?Channel Underlap 394

33.4 Summary 397

References 397

34 The Impact of a Fringing Field on the Device Performance of a P?Channel Tunnel Field?Effect Transistor with a High?κ Gate Dielectric 399

34.1 Introduction 399

34.2 Device Structure and Simulation 399

34.3 Results and Discussion 400

34.3.1 Effects of Variation in the Gate Dielectric Constant 400

34.3.2 Effects of Variation in the Spacer Dielectric Constant 408

34.4 Summary 410

References 410

35 Impact of a Spacer?Drain Overlap on the Characteristics of a Silicon Tunnel Field?Effect Transistor Based on Vertical Tunneling 412

35.1 Introduction 412

35.2 Device Structure and Process Steps 413

35.3 Simulation Setup 414

35.4 Results and Discussion 416

35.4.1 Impact of Variation in the Spacer?Drain Overlap 416

35.4.2 Influence of Drain on the Device Characteristics 424

35.4.3 Impact of Scaling 426

35.5 Summary 429

References 430

36 Gate?on?Germanium Source Tunnel Field?Effect Transistor Enabling Sub?0.5?V Operation 431

36.1 Introduction 431

36.2 Proposed Device Structure 431

36.3 Simulation Setup 432

36.4 Results and Discussion 434

36.4.1 Device Characteristics 434

36.4.2 Effects of Different Structural Parameters 435

36.4.3 Optimization of Different Structural Parameters 436

36.5 Summary 445

References 445

Part VIII PROSPECTS OF LOW?ENERGY DEVICE TECHNOLOLGY AND APPLICATIONS 447

37 Performance Comparison of Modern Devices 449

References 450

38 Emerging Device Technology and the Future of MOSFET 452

38.1 Studies to Realize High?Performance MOSFETs based on Unconventional Materials 452

38.2 Challenging Studies to Realize High?Performance MOSFETs based on the Nonconventional Doctrine 453

References 454

39 How Devices Are and Should Be Applied to Circuits 456

39.1 Past Approach 456

39.2 Latest Studies 456

References 457

40 Prospects for Low?Energy Device Technology and Applications 458

References 459

Bibliography 460

Index 463